246 lines
7.3 KiB
C
246 lines
7.3 KiB
C
/*
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* Symmetric key cipher operations.
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*
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* Generic encrypt/decrypt wrapper for ciphers, handles operations across
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* multiple page boundaries by using temporary blocks. In user context,
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* the kernel is given a chance to schedule us once per page.
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*
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* Copyright (c) 2015 Herbert Xu <herbert@gondor.apana.org.au>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the Free
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* Software Foundation; either version 2 of the License, or (at your option)
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* any later version.
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*
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*/
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#include <crypto/internal/skcipher.h>
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#include <linux/bug.h>
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#include <linux/module.h>
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#include "internal.h"
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static unsigned int crypto_skcipher_extsize(struct crypto_alg *alg)
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{
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if (alg->cra_type == &crypto_blkcipher_type)
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return sizeof(struct crypto_blkcipher *);
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BUG_ON(alg->cra_type != &crypto_ablkcipher_type &&
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alg->cra_type != &crypto_givcipher_type);
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return sizeof(struct crypto_ablkcipher *);
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}
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static int skcipher_setkey_blkcipher(struct crypto_skcipher *tfm,
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const u8 *key, unsigned int keylen)
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{
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struct crypto_blkcipher **ctx = crypto_skcipher_ctx(tfm);
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struct crypto_blkcipher *blkcipher = *ctx;
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int err;
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crypto_blkcipher_clear_flags(blkcipher, ~0);
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crypto_blkcipher_set_flags(blkcipher, crypto_skcipher_get_flags(tfm) &
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CRYPTO_TFM_REQ_MASK);
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err = crypto_blkcipher_setkey(blkcipher, key, keylen);
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crypto_skcipher_set_flags(tfm, crypto_blkcipher_get_flags(blkcipher) &
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CRYPTO_TFM_RES_MASK);
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return err;
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}
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static int skcipher_crypt_blkcipher(struct skcipher_request *req,
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int (*crypt)(struct blkcipher_desc *,
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struct scatterlist *,
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struct scatterlist *,
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unsigned int))
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{
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struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
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struct crypto_blkcipher **ctx = crypto_skcipher_ctx(tfm);
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struct blkcipher_desc desc = {
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.tfm = *ctx,
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.info = req->iv,
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.flags = req->base.flags,
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};
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return crypt(&desc, req->dst, req->src, req->cryptlen);
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}
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static int skcipher_encrypt_blkcipher(struct skcipher_request *req)
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{
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struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
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struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher);
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struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
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return skcipher_crypt_blkcipher(req, alg->encrypt);
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}
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static int skcipher_decrypt_blkcipher(struct skcipher_request *req)
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{
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struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
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struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher);
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struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
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return skcipher_crypt_blkcipher(req, alg->decrypt);
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}
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static void crypto_exit_skcipher_ops_blkcipher(struct crypto_tfm *tfm)
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{
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struct crypto_blkcipher **ctx = crypto_tfm_ctx(tfm);
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crypto_free_blkcipher(*ctx);
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}
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int crypto_init_skcipher_ops_blkcipher(struct crypto_tfm *tfm)
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{
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struct crypto_alg *calg = tfm->__crt_alg;
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struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm);
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struct crypto_blkcipher **ctx = crypto_tfm_ctx(tfm);
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struct crypto_blkcipher *blkcipher;
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struct crypto_tfm *btfm;
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if (!crypto_mod_get(calg))
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return -EAGAIN;
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btfm = __crypto_alloc_tfm(calg, CRYPTO_ALG_TYPE_BLKCIPHER,
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CRYPTO_ALG_TYPE_MASK);
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if (IS_ERR(btfm)) {
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crypto_mod_put(calg);
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return PTR_ERR(btfm);
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}
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blkcipher = __crypto_blkcipher_cast(btfm);
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*ctx = blkcipher;
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tfm->exit = crypto_exit_skcipher_ops_blkcipher;
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skcipher->setkey = skcipher_setkey_blkcipher;
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skcipher->encrypt = skcipher_encrypt_blkcipher;
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skcipher->decrypt = skcipher_decrypt_blkcipher;
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skcipher->ivsize = crypto_blkcipher_ivsize(blkcipher);
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return 0;
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}
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static int skcipher_setkey_ablkcipher(struct crypto_skcipher *tfm,
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const u8 *key, unsigned int keylen)
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{
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struct crypto_ablkcipher **ctx = crypto_skcipher_ctx(tfm);
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struct crypto_ablkcipher *ablkcipher = *ctx;
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int err;
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crypto_ablkcipher_clear_flags(ablkcipher, ~0);
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crypto_ablkcipher_set_flags(ablkcipher,
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crypto_skcipher_get_flags(tfm) &
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CRYPTO_TFM_REQ_MASK);
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err = crypto_ablkcipher_setkey(ablkcipher, key, keylen);
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crypto_skcipher_set_flags(tfm,
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crypto_ablkcipher_get_flags(ablkcipher) &
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CRYPTO_TFM_RES_MASK);
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return err;
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}
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static int skcipher_crypt_ablkcipher(struct skcipher_request *req,
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int (*crypt)(struct ablkcipher_request *))
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{
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struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
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struct crypto_ablkcipher **ctx = crypto_skcipher_ctx(tfm);
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struct ablkcipher_request *subreq = skcipher_request_ctx(req);
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ablkcipher_request_set_tfm(subreq, *ctx);
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ablkcipher_request_set_callback(subreq, skcipher_request_flags(req),
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req->base.complete, req->base.data);
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ablkcipher_request_set_crypt(subreq, req->src, req->dst, req->cryptlen,
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req->iv);
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return crypt(subreq);
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}
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static int skcipher_encrypt_ablkcipher(struct skcipher_request *req)
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{
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struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
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struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher);
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struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
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return skcipher_crypt_ablkcipher(req, alg->encrypt);
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}
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static int skcipher_decrypt_ablkcipher(struct skcipher_request *req)
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{
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struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
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struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher);
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struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
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return skcipher_crypt_ablkcipher(req, alg->decrypt);
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}
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static void crypto_exit_skcipher_ops_ablkcipher(struct crypto_tfm *tfm)
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{
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struct crypto_ablkcipher **ctx = crypto_tfm_ctx(tfm);
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crypto_free_ablkcipher(*ctx);
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}
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int crypto_init_skcipher_ops_ablkcipher(struct crypto_tfm *tfm)
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{
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struct crypto_alg *calg = tfm->__crt_alg;
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struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm);
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struct crypto_ablkcipher **ctx = crypto_tfm_ctx(tfm);
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struct crypto_ablkcipher *ablkcipher;
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struct crypto_tfm *abtfm;
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if (!crypto_mod_get(calg))
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return -EAGAIN;
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abtfm = __crypto_alloc_tfm(calg, 0, 0);
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if (IS_ERR(abtfm)) {
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crypto_mod_put(calg);
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return PTR_ERR(abtfm);
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}
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ablkcipher = __crypto_ablkcipher_cast(abtfm);
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*ctx = ablkcipher;
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tfm->exit = crypto_exit_skcipher_ops_ablkcipher;
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skcipher->setkey = skcipher_setkey_ablkcipher;
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skcipher->encrypt = skcipher_encrypt_ablkcipher;
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skcipher->decrypt = skcipher_decrypt_ablkcipher;
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skcipher->ivsize = crypto_ablkcipher_ivsize(ablkcipher);
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skcipher->reqsize = crypto_ablkcipher_reqsize(ablkcipher) +
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sizeof(struct ablkcipher_request);
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return 0;
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}
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static int crypto_skcipher_init_tfm(struct crypto_tfm *tfm)
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{
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if (tfm->__crt_alg->cra_type == &crypto_blkcipher_type)
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return crypto_init_skcipher_ops_blkcipher(tfm);
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BUG_ON(tfm->__crt_alg->cra_type != &crypto_ablkcipher_type &&
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tfm->__crt_alg->cra_type != &crypto_givcipher_type);
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return crypto_init_skcipher_ops_ablkcipher(tfm);
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}
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static const struct crypto_type crypto_skcipher_type2 = {
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.extsize = crypto_skcipher_extsize,
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.init_tfm = crypto_skcipher_init_tfm,
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.maskclear = ~CRYPTO_ALG_TYPE_MASK,
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.maskset = CRYPTO_ALG_TYPE_BLKCIPHER_MASK,
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.type = CRYPTO_ALG_TYPE_BLKCIPHER,
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.tfmsize = offsetof(struct crypto_skcipher, base),
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};
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struct crypto_skcipher *crypto_alloc_skcipher(const char *alg_name,
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u32 type, u32 mask)
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{
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return crypto_alloc_tfm(alg_name, &crypto_skcipher_type2, type, mask);
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}
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EXPORT_SYMBOL_GPL(crypto_alloc_skcipher);
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MODULE_LICENSE("GPL");
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MODULE_DESCRIPTION("Symmetric key cipher type");
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